Every once in a while, Plasma pops up a dozen error windows with the message "ksnapshot: Host not found".  They are harmless except for being very annoying.

Note that ksnapshot isn't even installed -- Arch Linux switched to spectacle some time ago.

Arch Linux standard packages, plasma 5.6.4, KF5 5.22.0. 

Reproducible: Sometimes

Steps to Reproduce:
Wait while logged into plasma.

Actual Results:  
Dozens of "ksnapshot: Host not found" error messages pop up every once in a while.

Expected Results:  
Nothing happens.

journalctl -xl output that may be relevant:

May 27 16:15:41 maxwell-arch plasmashell[803]: org.kde.plasma.pulseaudio: PROPERTY CHANGED ( 0 ) ::  270 "ActivePortIndex"
May 27 16:15:41 maxwell-arch plasmashell[803]: org.kde.plasma.pulseaudio: returning roles QHash((259, "ObjectName")(258, "PulseObject")(269, "Ports")(268, "CardIndex")(270, "ActivePortIndex")(265, "VolumeWritab
May 27 16:15:41 maxwell-arch plasmashell[803]: org.kde.plasma.pulseaudio: PROPERTY CHANGED ( 0 ) ::  261 "Properties"
May 27 16:15:41 maxwell-arch plasmashell[803]: org.kde.plasma.pulseaudio: returning roles QHash((259, "ObjectName")(258, "PulseObject")(269, "Ports")(268, "CardIndex")(270, "ActivePortIndex")(265, "VolumeWritab
May 27 16:15:41 maxwell-arch plasmashell[803]: org.kde.plasma.pulseaudio: PROPERTY CHANGED ( 0 ) ::  262 "Volume"
May 27 16:15:41 maxwell-arch plasmashell[803]: org.kde.plasma.pulseaudio: returning roles QHash((259, "ObjectName")(258, "PulseObject")(269, "Ports")(268, "CardIndex")(270, "ActivePortIndex")(265, "VolumeWritab
May 27 16:15:41 maxwell-arch plasmashell[803]: org.kde.plasma.pulseaudio: PROPERTY CHANGED ( 0 ) ::  268 "CardIndex"
May 27 16:15:41 maxwell-arch plasmashell[803]: org.kde.plasma.pulseaudio: returning roles QHash((259, "ObjectName")(258, "PulseObject")(269, "Ports")(268, "CardIndex")(270, "ActivePortIndex")(265, "VolumeWritab
May 27 16:15:41 maxwell-arch plasmashell[803]: org.kde.plasma.pulseaudio: PROPERTY CHANGED ( 0 ) ::  269 "Ports"
May 27 16:15:41 maxwell-arch plasmashell[803]: org.kde.plasma.pulseaudio: returning roles QHash((259, "ObjectName")(258, "PulseObject")(269, "Ports")(268, "CardIndex")(270, "ActivePortIndex")(265, "VolumeWritab
May 27 16:15:41 maxwell-arch plasmashell[803]: org.kde.plasma.pulseaudio: PROPERTY CHANGED ( 0 ) ::  270 "ActivePortIndex"
May 27 16:15:41 maxwell-arch plasmashell[803]: Could not find service for job "Job 4" with app name "org.kde.kded5"
May 27 16:15:41 maxwell-arch plasmashell[803]: qml:  totalCountChanged 2
May 27 16:15:41 maxwell-arch plasmashell[803]: Currrent active notifications: QHash(("notification 1", "kded5Transferring: Failed"))
May 27 16:15:41 maxwell-arch plasmashell[803]: Guessing partOf as: 1
May 27 16:15:41 maxwell-arch plasmashell[803]:  New Notification:  "Transferring: Failed" "ksnapshot: Host not found" 0 & Part of: 1
May 27 16:15:41 maxwell-arch plasmashell[803]: qml:  totalCountChanged 1
May 27 16:15:41 maxwell-arch plasmashell[803]: qml:  totalCountChanged 2
May 27 16:15:41 maxwell-arch plasmashell[803]: Could not find service for job "Job 17" with app name "org.kde.kded5"
May 27 16:15:41 maxwell-arch plasmashell[803]: qml:  totalCountChanged 1
May 27 16:15:41 maxwell-arch plasmashell[803]: Currrent active notifications: QHash(("notification 1", "kded5Transferring: Failed"))
May 27 16:15:41 maxwell-arch plasmashell[803]: Guessing partOf as: 1
May 27 16:15:41 maxwell-arch plasmashell[803]:  New Notification:  "Transferring: Failed" "ksnapshot: Host not found" 0 & Part of: 1
May 27 16:15:41 maxwell-arch plasmashell[803]: qml:  totalCountChanged 0
May 27 16:15:42 maxwell-arch plasmashell[803]: qml:  totalCountChanged 1
May 27 16:15:42 maxwell-arch plasmashell[803]: file:///usr/share/plasma/plasmoids/org.kde.plasma.battery/contents/ui/batterymonitor.qml: QML Plasmoid: Cannot anchor to an item that isn't a parent or sibling.
May 27 16:15:42 maxwell-arch plasmashell[803]: file:///usr/share/plasma/plasmoids/org.kde.plasma.battery/contents/ui/batterymonitor.qml: QML Plasmoid: Cannot anchor to an item that isn't a parent or sibling.
May 27 16:15:42 maxwell-arch plasmashell[803]: file:///usr/share/plasma/plasmoids/org.kde.plasma.battery/contents/ui/batterymonitor.qml: QML Plasmoid: Cannot anchor to an item that isn't a parent or sibling.
May 27 16:15:42 maxwell-arch plasmashell[803]: file:///usr/share/plasma/plasmoids/org.kde.plasma.battery/contents/ui/batterymonitor.qml: QML Plasmoid: Cannot anchor to an item that isn't a parent or sibling.
May 27 16:15:43 maxwell-arch plasmashell[803]: org.kde.plasma.pulseaudio: returning roles QHash((259, "ObjectName")(258, "PulseObject")(269, "Ports")(268, "CardIndex")(270, "ActivePortIndex")(265, "VolumeWritab
May 27 16:15:43 maxwell-arch plasmashell[803]: org.kde.plasma.pulseaudio: PROPERTY CHANGED ( 0 ) ::  261 "Properties"
May 27 16:15:43 maxwell-arch plasmashell[803]: org.kde.plasma.pulseaudio: returning roles QHash((259, "ObjectName")(258, "PulseObject")(269, "Ports")(268, "CardIndex")(270, "ActivePortIndex")(265, "VolumeWritab
May 27 16:15:43 maxwell-arch plasmashell[803]: org.kde.plasma.pulseaudio: PROPERTY CHANGED ( 0 ) ::  262 "Volume"
May 27 16:15:43 maxwell-arch plasmashell[803]: org.kde.plasma.pulseaudio: returning roles QHash((259, "ObjectName")(258, "PulseObject")(269, "Ports")(268, "CardIndex")(270, "ActivePortIndex")(265, "VolumeWritab
May 27 16:15:43 maxwell-arch plasmashell[803]: org.kde.plasma.pulseaudio: PROPERTY CHANGED ( 0 ) ::  268 "CardIndex"
May 27 16:15:43 maxwell-arch plasmashell[803]: org.kde.plasma.pulseaudio: returning roles QHash((259, "ObjectName")(258, "PulseObject")(269, "Ports")(268, "CardIndex")(270, "ActivePortIndex")(265, "VolumeWritab
May 27 16:15:43 maxwell-arch plasmashell[803]: org.kde.plasma.pulseaudio: PROPERTY CHANGED ( 0 ) ::  269 "Ports"
May 27 16:15:43 maxwell-arch plasmashell[803]: org.kde.plasma.pulseaudio: returning roles QHash((259, "ObjectName")(258, "PulseObject")(269, "Ports")(268, "CardIndex")(270, "ActivePortIndex")(265, "VolumeWritab
May 27 16:15:43 maxwell-arch plasmashell[803]: org.kde.plasma.pulseaudio: PROPERTY CHANGED ( 0 ) ::  270 "ActivePortIndex"